The invention relates to a propeller shaft assembly for connecting the front gearbox output to the drive input of the rear axle drive of a motor vehicle, especially of a passenger car.
Such propeller shaft assemblies known from the technical literature, for example Prof. Dipl.-Ing. Jornson Reimpell: Fahrwerktechnik 1, 5.sup.th edition, Vogel-Verlag, p. 285, FIG. 3.1/21, comprise two propeller shaft portions which are connected to one another by a constant velocity plunging joint. At the ends of the propeller shaft portions intended to be connected to the front gearbox output and to the rear drive input, there are arranged universal joints. The propeller shaft serving to be connected to the gearbox output is associated with a resilient intermediate bearing which serves for additionally supporting the propeller shaft assembly on the floor assembly of the motor vehicle. The connection at the front end between the universal joint and the gearbox output is effected by a sleeve which is associated with a joint yoke of the universal joint and which comprises a bore with longitudinal toothing by means of which it is slid onto a correspondingly toothed shaft in the neck of the gearbox output. The constant velocity plunging joint connecting the two propeller shaft portions permits angular movements as well as displacing movements between the inner joint part and the outer point part, so that any changes in distance and position between the intermediate bearing and the rear drive input are compensated for. However, the resistance against such displacement is high.
In the assembly described, the smooth running characteristics are improved as compared to those propeller shaft assemblies wherein the between the two propeller shaft portions is a universal joint, but any movement vibrations generated by the gearbox, by the axle drive of the rear axle and resulting from the displacement of the articulation center of the universal joint, are transmitted by the front and rear propeller shaft portions into the attached assemblies. The intermediate bearing is also excited by vibrations.
The propeller shaft assembly is subject to movement vibrations and structure-borne sound vibrations introduced by the gearbox output and the rear drive input. In addition, as far as the rear propeller shaft portion is concerned, there are temporarily increased articulation angles. The problem is that constantly changing torque values and rotational speeds are transmitted from the front engine and gearbox unit to the rear axle. Load values suddenly increasing to 10 times the nominal torque, and rotational speeds up to 10,000 revolutions per minute are no rarity.